This invention relates to a multistage process for the removal of stains from fabrics, more especially from fabrics such as carpets and carpeted floors.
In addition to shampoos, powder-form cleaning compositions have recently been used to an increasing extent for the cleaning in place of carpets and other fabric coverings. The powder-form compositions have the advantage of leaving behind no rings and of drying more quickly. The principal constituents of such cleaning powders are surfactants and absorbents, and also relatively large quantities of water in loosely bound form. The surfactants in combination with the water are assumed to be responsible for the detachment of the soil particles from the fibers and for their transport to the absorbent which, after the water has dried, is removed together with the soil either by brushing or by vacuum cleaning. Examples of such powder-form cleaning compositions can be found in Austrian Patent specification 296,477, in U.S. Pat. No. 4,648,882 and in U.S. Pat. No. 4,659,494. These known compositions achieve a high standard in regard to cleaning large carpet areas and convenient handling. However, a problem with powder-form fabric cleaning compositions is that stains on the fabrics are often not fully removed during the surface cleaning process and remain visible, even after the cleaning composition has been removed by brushing or by vacuum cleaning. Hitherto, it has not been possible to satisfactorily overcome this disadvantage even by prespotting with the powder-form cleaning compositions.
On the other hand, there are many known compositions specifically formulated for the removal of stains from fabrics which are applied in liquid or paste-like form for the local treatment of the stained areas. These known compositions can vary widely in composition from pure solvent mixtures to purely aqueous surfactant solutions. Examples of compositions such as these can be found in German Offenlegungsschrift 32 25 190 and in U.S. Pat. Nos. 3,764,544 and 4,124,542. The disadvantage of these compositions is that, in many cases, they only act on certain types of stain or, in the case of broad-spectrum formulations, promote intensified re-soiling of the treated areas. In the case of colored stains, enlargement of the stained area and subsequent rim formation often occur as well. Particularly troublesome is the formation of rings which, in many cases, is in evidence even when the original stain has been completely removed. Like the remaining stains, rings and rims are difficult or impossible to subsequently remove with powder-form fabric cleaning compositions.
Accordingly, an object of the present invention is to provide an improved stain removal process.
A further object of the invention is to provide an improved stain cleaning process for carpets and other fabrics which avoids the formation of rims or rings around stained areas after completion of the cleaning process.
Yet another object is the provision of a unitary package of separately packaged stain removal and powder compositions formulated for separate application to surfaces to be cleaned.
These and other objects of the invention will become evident from the following description.